Peristaltic pump

ABSTRACT

A peristaltic pump utilizing a fluid inlet from a source of fluid which communicates with a flexible conduit. The flexible conduit is compressed utilizing a motor which rotates a shaft. An eccentric member is locked to the shaft and contacts the inner race of a bearing which is circumferentially located relative to the eccentric member. The outer race of the bearing contacts a lifter which squeezes the conduit against a fixed plate. A check valve arrangement assures flow through the conduit in one direction.

BACKGROUND OF THE INVENTION

Peristaltic pumps have been devised to provide a steady flow of fluidthrough a conduit by pressing a member along the length of the conduit.In the past, moveable members have been rolled along the length of theconduit to squeeze fluid from the same in aliquot amounts. For example,U.S. Pat. Nos. 5,064,358 and 5,620,313 describe this type of peristalticpump. Unfortunately, such peristaltic pumps have suffered from lowpressure outputs and pulses or surges which render such pumps asunsuitable for analytical, preparatory or other uses.

U.S. Pat. Nos. 4,365,943 and 5,033,943 show peristaltic pumps having lowflow rates which utilize a rotating shaft to turn a cam that eitherdirectly or indirectly contacts a plurality of flexible conduitssequentially. In either case a relatively small portion of such flexibleconduits are deformed to produce the flow.

A peristaltic pump which exhibits high flow rate characteristics andeliminates surge would be a notable advance in the field of masstransport.

SUMMARY OF THE INVENTION

In accordance with the present invention a novel and useful peristalticpump for delivery of fluid from a source is herein provided.

The pump of the present invention utilizes a fluid inlet which passesfluid from a source such as a reservoir. The fluid inlet communicateswith a flexible conduit having an elongated dimension. Such flexibleconduit further includes a fluid outlet. In many cases, a plurality offlexible conduits may be employed and are located in spaced relationshipfrom one another.

Compressing means is also used for pressing the flexible conduit orconduits. Such compressing means utilizes a motor and a shaft which isaxially rotated by the motor. A first eccentric member is locked to therotating shaft, and a plate is located adjacent the flexible conduit. Inopposition to the plate is a conduit lifter which is capable of beingpositioned adjacent the flexible conduit and being moved toward and awayfrom the flexible conduit. The conduit lifter, thus, sandwiches orsqueezes the flexible conduit to the stationary plate to cause flow offluid through the flexible conduit. A first bearing having an inner racecontacts the first eccentric member. The outer race of the first bearingengages the conduit lifter. Thus, rotation of the eccentric member movesthe bearing into contact with the conduit lifter to squeeze the conduitduring certain portions of rotation of the shaft of the motor. Suchsqueezing or collapse of the flexible conduit, in part, against theplate causes fluid to flow through the conduit. Check valve meansdirects flow of the fluid in one direction.

In certain embodiments of the present invention, the conduit lifter mayinclude at least one protuberance which extends toward and contacts theouter race of the first bearing. Where a second bearing is employed, theconduit lifter may include a second protuberance contacting the outerrace of the second bearing. In such a case, the second bearing wouldalso be located in circumferential relationship with a second eccentricmember locked to the shaft of the motor. Thus, a pair of bearings wouldoperate a single conduit lifter to cause flow through the conduit inthis embodiment.

In addition, where a second flexible conduit is employed in the presentinvention, the first eccentric member may support at least another, orthird, bearing which would contact a second conduit lifter radiallyseparated about the axis of the shaft from the first conduit lifter.Separation between the flexible conduits and associated lifters may bedetermined in order to pump fluid through the second conduit when thefirst conduit has already begun discharging of fluid. Thus, a continuousflow of fluid is obtained from the pump of the present invention. Inaddition, more than two conduits may be employed in the presentinvention in sequential fashion, each conduit being operated by a singleshaft and by both eccentric members. Again, bearings may independentlycontact each conduit lifter associated with each flexible conduit aboutthe axis of rotation of the shaft of the motor. Locking collars may holdthe multiple bearings location relative to each of the eccentricmembers. Locking collars may also be located about the motor shaft andabout the outer surface of any of the eccentric members.

It may be apparent that a novel and useful peristaltic pump has beendescribed hereinabove.

It is therefore and object of the present invention to provide aperistaltic pump for delivery of fluid from a source that utilizes amultiplicity of flexible conduits which are sequentially activated toproduce steady flow of fluid.

Another object of the present invention is to provide a peristaltic pumpfor delivery of fluid from a source which is capable of delivery offluid at relatively high pressures.

Another object of the present invention is to provide a peristaltic pumpfor delivery of fluid from a source which greatly eliminates surge orpulsation associated with the flow of fluid from peristaltic pumps ofthe prior art.

A further object of the present invention is to provide a peristalticpump which utilizes multiple eccentric members located on a shaft tooperate a single conduit lifter in order to maximize the volume of flowtherefrom.

Yet another object of the present invention is to provide a peristalticpump which is sturdy and may be employed in rugged environments.

Another object of the present invention is to provide a peristaltic pumpwhich is extremely durable at high speeds of operation.

Another object of the present invention is to provide a peristaltic pumpthat may be simply retrofitted with components to alter flow rate andpressure parameters of operation.

The invention possesses other objects and advantages especially asconcerns particular characteristics and features thereof which willbecome apparent as the specification continues.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of the embodiment of the presentinvention with a portion of the lifter supports shown in section.

FIG. 2 is a sectional view showing the sequential operation of theperistaltic pump of FIG. 1 taken along line 2—2 of FIG. 1.

FIG. 3 is a top plan schematic view of the flow pattern of the pumpdepicted in the prior figures.

For a better understanding of the invention reference is made to thefollowing detailed description of the preferred embodiments thereofwhich should be taken in conjunction with the prior described drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Various aspects of the present invention will evolve from the followingdetailed description of the preferred embodiments which should bereferenced to the hereinbefore delineated drawings.

The invention as a whole is depicted in the drawings by referencecharacter 10. The peristaltic pump 10 includes as one of its elements afluid inlet 12 which may feed from a fluid reservoir (not shown). Fluidinlet 12 flows through a manifold 14 which essentially splits fluidinlet 12 into multiple streams. In the embodiment 10 depicted in FIGS.1-3, fluid inlet 12 has been split into four separate streams, 16, 18,20, and 22, shown schematically in FIG. 3. FIG. 1 depicts fluid streams16 and 22 most clearly. Directional arrows 24 illustrate the split ofinlet stream 12. Check valve means 26 insures the flow of fluid frominlet 12 from outlet 28 in one direction through the action of pump 10.This operation will be described in greater detail hereinafter.Directional arrow 30 shows the flow of fluid from pump 10, in thisregard. Again, FIG. 3 depicts check valve means 26, schematically, withrespect to fluid stream 16, 18, 20, and 22. That is to say, check valves32 and 34 are associated with fluid stream 16, while check valves 36 and38 are associated with fluid stream 22. Similar check valves operatewith respect to fluid streams 18 and 20. Manifold 40 combines the flowfrom fluid stream 16, 18, 20, and 22 into fluid outlet 28. Eductor 29may connect inlet 12 with outlet 28, to allow a small portion of outletfluid to travel back to the inlet stream. Eductor 29 permits pump 10 torun at high speeds, which will be discussed more fully hereinafter.

Each fluid stream, 16, 18, 20, and 22 has an associated flexibleconduit. Turning to FIG. 2, it may be observed that flexible conduits42, 44, 46, and 48 are associated with fluid streams 16, 18, 20, and 22,respectively. For the sake of clarity, FIG. 1 depicts flexible conduits42 and 46 most clearly. Flexible conduits 42 and 46 are elongated andcommunicate with fluid inlet 12 as well as fluid outlet 28. Thus,exemplary conduit 42 includes a fluid inlet portion 50 and a fluidoutlet portion 52. The same relationship exists with respect to flexibleconduits 44, 46, and 48. Each conduit may range in size from 1 inch to 5inches in diameter and be able to withstand pressure up to 2,500 psi.For example, conduits 42, 44, 46, and 48 may take the form of industrialhoses composed of elastomeric material having multiple high tensilestrength steel belts imbedded within the hose wall.

Compressing means 54 is utilized to sequentially press or collapseconduits 40, 42, 44, 46, and 48. It may be apparent from FIG. 1 thatcompressing means utilizes a motor 56 which may be operatedelectrically, through an internal combustion mechanism, by manual means,and the like. In any case, motor 56 rotates the output shaft 58. Shaft58 is held to journals 60 and 62 and maintained in this position bysupports 64 and 66.

Locked to shaft 58 are a pair of eccentric members 68 and 70, whichnecessarily, rotate with shaft 58. A plurality of bearings 72 and aplurality of bearings 74 are associated with first eccentric member 68and second eccentric member 70, respectively. Turning to FIG. 2, it maybe seen that bearings 76 and 78 are employed to collapse or squeezeflexible conduit 42. In such a case, compressing means 54 takes the formof a conduit or hose lifter 80 which is movable upwardly and downwardlyaccording to directional arrow 82, FIG. 2. A plurality of rollers 84fixed to journals 60 and 62 allow lifter 80 to move up and down. Itshould be noted that a fixed plate 86 lies in opposition to conduitlifter 80 to effect the squeezing or collapsing of conduit 42, bestshown in FIGS. 1 and 2. Consequently, plate 88 and lifter 90 collapseconduit 44, plate 92 and lifter 94 collapse conduit 46, and plate 96 andlifter 98 collapse conduit 48, in a sequential manner as shaft 58 turns.Although the actual mechanism for such squeezing or collapsing has beenthoroughly discussed with respect to conduit 42 and it should beunderstood that a similar mechanism applies to the squeezing of theremaining conduits. Eductor 29 allows conduits 42, 44, 46, and 48 toquickly expand with fluid and rebound from a collapsed state when pump10 runs at elevated speeds.

Conduit lifter 80 is provided with a pair of protuberances or blocks 100and 102 which contact the outer races of bearings 76 and 78. Viewingagain, FIG. 2, bearing 76 is shown in greater detail, in which outerrace 104 rotates relative to inner race 106. Plurality of ball bearings108 lie in between outer race 104 and inner race 106. Blocks 100 and 102allow the use of lifter 80 against elongated portion of conduit 42,which maximizes the flow of fluid therefrom. It should be further seenthat bar 103 may be employed to connect lifters 80 and 94 together. Ithas been found that multiple bearing sets acting on individual liftersreduce friction, conserving energy, and prolong the life of the movingcomponents of pump 10.

In operation, with respect to conduit 42 and compressing means 54associated therewith, motor 56 turns shaft 58 and eccentric member 68locked thereto. Bearings 76 and 78 are moved upwardly, in FIG. 2, suchthat the outer races of such bearings, including outer race 104 ofbearing 76, contact block 100 and block 102 formed on conduit lifter 80.When this occurs, lifter 80 squeezes conduit 42 against plate 86 suchthat fluid flows from conduit 42 according to directional arrow 30through outlet 28. The direction of such flow is due to check valvemeans 26. As shaft 58 turns according to directional arrow 110, lifter80 retreats toward shaft 58 and lifter 90 begins to collapse or squeezeconduit 44. At this point, conduit 46 is in its fully extended positionbetween lifter 94 and plate 92. However, when shaft 58 continues toturn, conduit 46 will be collapsed between lifter 94 and plate 92 toforce liquid from conduit 46 through outlet 28. The sequentialcollapsing of conduits 42, 44, 46, and 48 produces a high volume steadyflow of fluid through outlet 28. Following collapse, each conduit 42,44, 46, and 48 quickly expand due to the elastomeric material and thehigh tensile strength steel embedded in the conduit wall. Eductor 29also aids in this endeavor. Pump 10 may be easily retrofitted withhoses, lifters, bearings, and the like, to meet particular operationdemands of flow rate and pressure.

While in the foregoing, embodiments of the present invention have beenset forth in considerable detail for the purposes of making a completedisclosure of the invention, it may be apparent to those of skill in theart that numerous changes may be made in such detail without departingfrom the spirit and principles of the invention.

What is claimed is:
 1. A peristaltic pump for delivering fluid from asource, comprising: a. a fluid inlet, said fluid inlet passing fluidfrom the source; b. a first flexible conduit having an elongateddimensions said first flexible conduit being connected to andcommunicating with said fluid inlet, said first flexible conduit furtherincluding a fluid outlet; c. a second flexible conduit having anelongated dimension, said second flexible conduit being connected tosaid fluid inlet, said second flexible conduit further including a fluidoutlet, said second flexible conduit being spaced from said firstflexible conduit; d. compressing means for pressing said flexibleconduit, said compressing means comprising a motor, a shaft axiallyrotated by said motors at least a first eccentric member locked to saidrotating shaft, a first plate located adjacent said first flexibleconduit and a first conduit lifter located adjacent said first flexibleconduit and in opposition to said first plate, a second plate locatedadjacent said second flexible conduit, and a second conduit lifterlocated adjacent said second flexible conduit and in opposition to saidsecond plate, said first conduit lifter contacting only said firstflexible conduit along said elongated dimension of said first flexibleconduit, said second conduit lifter contacting only said second flexibleconduit along said elongated dimension of said second flexible conduit,a first bearing, said first bearing having an inner race contacting saidfirst eccentric member and an outer race contacting said first conduitlifter to move said first conduit lifter and for directing a forceagainst said first flexible conduit to at least partially collapse saidfirst flexible conduit against said first plate during one portion ofthe axial rotation of said shaft, and a second bearing, said secondbearing having an inner race contacting said first eccentric member andan outer race contacting said second conduit lifter to move said secondconduit lifter and for directing a force against said second flexibleconduit to at least partially collapse said second flexible conduitagainst said second plate during one portion of the axial rotation ofsaid shaft; and d. check valve means to direct fluid in one direction insaid first and second flexible conduits.
 2. The pump of claim 1 in whichsaid conduit lifter further comprises a protuberance extending towardsaid outer race of said first bearing.
 3. The pump of claim 1 in whichsaid compressing means further comprises a second eccentric memberlocked to said rotating shaft and spaced from said first eccentricmember, a second bearing, said second bearing having an inner racecontacting said second eccentric member and an outer race contactingsaid conduit lifter simultaneously with said contact of said conduitlifter by said outer race of said first bearing.
 4. The pump of claim 3in which said conduit lifter further comprises a first protuberanceextending toward and contacting said outer race of said first bearingand a second protuberance extending toward and contacting said outerrace of said second bearing.
 5. The pump of claim 4 which furthercomprises a pair of locking collars at least partially surrounding saidshaft and supporting said first bearing to said first eccentric memberlocked to said rotating shaft.
 6. The pump of claim 5 in which saidconduit lifter further comprises track means for guiding said movementof said conduit lifter.
 7. The pump of claim 1 in which said flexibleconduit is a first flexible conduit and which further comprises a secondflexible conduit, having an elongated dimension, communicating with saidfluid inlet, said second flexible conduit further including a fluidoutlet, said plate is a first plate and further includes a second platelocated adjacent said second flexible conduit, said conduit lifter is afirst conduit lifter and further includes a second conduit liftercontacting said second flexible conduit along said elongated dimensionof said second flexible conduit, a third bearing having an inner racecontacting said first eccentric member locked to said rotating shaft,and an outer race contacting said second conduit lifter, said outer raceof said third bearing moving said second conduit lifter to at leastpartially collapse said second flexible conduit against said secondplate during another portion of the axial rotation of said shaft, andsaid check valve means directing fluid in one direction in said secondflexible conduit.
 8. The pump of claim 7 in which said first conduitlifter further comprises a protuberance extending toward said outer raceof said first bearing.
 9. The pump of claim 8 in which said compressingmeans further comprises a second eccentric member locked to saidrotating shaft and spaced from said first eccentric member, a secondbearing, said second bearing having an inner race contacting said secondeccentric member and an outer race contacting said first conduit liftersimultaneously with said contact of said first conduit lifter by saidouter race of said first bearing.
 10. The pump of claim 9 in which saidprotuberance is a first protuberance and which further comprises asecond protuberance extending toward and contacting said outer race ofsaid second bearing.
 11. The pump of claim 10 which further comprises apair of locking collars at least partially surrounding said shaft andsupporting said first and third bearings to said first eccentric memberlocked to said rotating shaft.
 12. The pump of claim 11 which furthercomprises a manifold receiving said fluid outlets of said first andsecond flexible conduits.
 13. The pump of claim 1 which further includesan eductor conduit communicating with said fluid inlet and said fluidoutlet.
 14. A peristaltic pump for delivering fluid from a source,comprising: a. a fluid inlet, said fluid inlet passing fluid from thesource; b. a first flexible conduit having an elongated dimension, saidfirst flexible conduit being connected to and communicating with saidfluid inlet, said first flexible conduit further including a fluidoutlet; c. a second flexible conduit having an elongated dimension, saidsecond flexible conduit being connected to said fluid inlet, said secondflexible conduit further including a fluid outlet, said second flexibleconduit being spaced from said first flexible conduit; d. compressingmeans for pressing said flexible conduit, said compressing meanscomprising a motor, a shaft axially rotated by said motor, a firsteccentric member locked to said rotating shaft, a second eccentricmember locked to said rotating shaft, a first plate located adjacentsaid first flexible conduit and a first conduit lifter located adjacentsaid first flexible conduit and in opposition to said first plate, asecond plate located adjacent said second flexible conduit, and a secondconduit lifter located adjacent said second flexible conduit and inopposition to said second plate, said first conduit lifter contactingonly said first flexible conduit along said elongated dimension of saidfirst flexible conduit, said second conduit lifter contacting only saidsecond flexible conduit along said elongated dimension of said secondflexible conduit, a first bearing, said first bearing having an innerrace contacting said first eccentric member and an outer race contactingsaid first conduit lifter to move said first conduit lifter and fordirecting a force against said first flexible conduit to at leastpartially collapse said first flexible conduit against said first plateduring one portion of the axial rotation of said shaft, and a secondbearing, said second bearing having an inner race contacting said secondeccentric member and an outer race contacting said second conduit lifterto move said second conduit lifter and for directing a force againstsaid second flexible conduit to at least partially collapse said secondflexible conduit against said second plate during one portion of theaxial rotation of said shaft; and d. check valve means to direct fluidin one direction in said first and second flexible conduits.